microwave technology

Timco

Surely there must be a safer way of feeling warm & fuzzy inside. I always thought a giant magnifying glass over a house with a way to raise & lower it based on t-stat demand would work but there must be a way to limit the magnification so you don't end up like countless bugs I encountered as a kid...

Tim

Timco

As I warm my lunch, I am wondering if there is a reason I am missing why no one has explored the possibility of microwave technology for a boiler? Seems that would make a cheap, electric boiler.

Tim

nicholas bonham-carter

microwave

also very good for washing machines--nbc

Doug_7

Microwave Boiler

A microwave generator is not very efficient in convering electrical power input into microwave output and ultimately into hot water.

There are a lot of losses in the power conversion step necessary to supply the microwave generator, then more losses in the microwave generator itself. Overall efficiency of power input to useful heat output may be 40 to 50% at best.

Electrical resistance heaters are said to be 100% efficient.

Microwave ovens offer lots of convenience and are still the most efficient way to heat food - more efficient than stoves and ovens.

Timco

It just seems that even with the power loss, it does it's job soo fast that it would make sense. Has anyone else heard the story of the exploding glass of water heated in a microwave? It was supposed to have 'built up energy' and there was some warning about heating water in the microwave...

Tim

Gordy

scenerio

There have been people scalded when taking a cup of boiling water out of the microwave, and sticking a cold metal spoon into the cup. A very violent reaction can occur, which basically sends water spraying all over.


Gordy

Mike T., Swampeast MO

Clean, pure water can easily be heated well above the boiling point without boiling in a microwave.

Distilled water works best, but tap water sometimes works. Just add some to a clean mug and heat for a few minutes on high. The water will be steaming but not boiling. Then carefully add some "impurity" like a toothpick broken in half and you'll get a quite violent reaction.

The explanation I read was that the bubbles of boiling have to form around some sort of impurity.

As others mentioned, there are inefficiencies in producing microwaves from electricity that do not exist with simple electric resistance.

Should microwave clothes driers ever prove practical (they've been promised for many years) they will be quite efficient as they will only heat the water in the clothing thus evaporating it.

jp_2

100 % eff. but....

the electric stove may be 100% at converting electricity into heat. but is the stove/tea kettle 100% efficient at transferring that heat?

this is where it seems the microwave is more efficient?

Doug_7

The electric stove is 100% efficient at converting electricity into heat, but there are lots of heat losses from the burner and tea kettle into the air, so the whole process is not so efficient.

A gas stove is cheaper to operate, gas being cheaper tahn electricity per heating unit..

A Microwave is very efficient in converting microwaves into hot water - almost all the heat goes into the water, but there are inefficiencies in the power supply and microwave generator.

The microwave may be more efficient than a kettle on the stove, but an electric kettle will be more efficient than either, due to the immersed heating element - unless you put too much water in the kettle and waste this heat - which happens. Boil twice as much waater as you need and the overall efficiency drops to less than 50%.

The microwave gets my vote for speed and convenience. For top efficiency use an electric kettle with a measured amount of water to be heated. I think they are starting to make these.

Doug

bob_46

Timco

why bother with a boiler? Why not heat the occupants of the structure directly with microwaves?